KernelLand/Modules/USB/Core/usb_poll.c

   1 /*
   2  * Acess2 USB Stack
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * usb_poll.c
   6  * - Endpoint polling
   7  */
   8 #define DEBUG   1
   9 #include <usb_core.h>
  10 #include "usb.h"
  11 #include <timers.h>
  12
  13 #define POLL_ATOM       25      // 25ms atom
  14 #define POLL_MAX        256     // Max period that can be nominated
  15 #define POLL_SLOTS      ((int)(POLL_MAX/POLL_ATOM))
  16
  17 // === IMPORTS ===
  18 extern tUSBHost *gUSB_Hosts;
  19
  20 // === PROTOTYPES ===
  21 void    USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint);
  22
  23 // === GLOBALS ===
  24 tUSBEndpoint    *gUSB_PollQueues[POLL_MAX/POLL_ATOM];
  25  int    giUSB_PollPosition;     // Index into gUSB_PollQueues
  26
  27 // === CODE ===
  28 void USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint)
  29 {
  30         tUSBEndpoint    *endpt;
  31
  32         // Some sanity checks
  33         if(Endpoint <= 0 || Endpoint > Iface->nEndpoints)       return ;
  34         endpt = &Iface->Endpoints[Endpoint-1];
  35         if(endpt->PollingPeriod > POLL_MAX || endpt->PollingPeriod <= 0)
  36                 return ;
  37
  38         // TODO: Check that this endpoint isn't already on the queue
  39
  40         endpt->InputData = malloc(endpt->MaxPacketSize);
  41
  42         // Determine polling period in atoms
  43         endpt->PollingAtoms = (endpt->PollingPeriod + POLL_ATOM-1) / POLL_ATOM;
  44         if(endpt->PollingAtoms > POLL_SLOTS)    endpt->PollingAtoms = POLL_SLOTS;
  45         // Add to poll queue
  46         // TODO: Locking
  47         {
  48                  int    idx = giUSB_PollPosition + 1;
  49                 if(idx >= POLL_SLOTS)   idx -= POLL_SLOTS;
  50                 endpt->Next = gUSB_PollQueues[idx];
  51                 gUSB_PollQueues[idx] = endpt;
  52         }
  53 }
  54
  55 /**
  56  * \brief USB polling thread
  57  */
  58 int USB_PollThread(void *unused)
  59 {
  60         Threads_SetName("USB Polling Thread");
  61         for(;;)
  62         {
  63                 tUSBEndpoint    *ep, *prev;
  64
  65                 if(giUSB_PollPosition == 0)
  66                 {
  67                         // Check hosts
  68                         for( tUSBHost *host = gUSB_Hosts; host; host = host->Next )
  69                         {
  70                                 host->HostDef->CheckPorts(host->Ptr);
  71                         }
  72                 }
  73
  74 //              Log_Debug("USBPoll", "giUSB_PollPosition = %i", giUSB_PollPosition);
  75
  76                 // A little evil for neater code
  77                 prev = (void*)( (tVAddr)&gUSB_PollQueues[giUSB_PollPosition] - offsetof(tUSBEndpoint, Next) );
  78
  79                 // Process queue
  80 //              LOG("giUSB_PollPosition = %i", giUSB_PollPosition);
  81                 for( ep = gUSB_PollQueues[giUSB_PollPosition]; ep; prev = ep, ep = ep->Next )
  82                 {
  83                          int    period_in_atoms = ep->PollingAtoms;
  84 //                      LOG("%i: ep = %p", giUSB_PollPosition, ep);
  85
  86                         // Check for invalid entries
  87                         if(period_in_atoms < 0 || period_in_atoms > POLL_ATOM)
  88                         {
  89                                 Log_Warning("USB", "Endpoint on polling queue with invalid period");
  90                                 continue ;
  91                         }
  92                         // Check for entries to delete
  93                         if(period_in_atoms == 0)
  94                         {
  95                                 // Remove
  96                                 prev->Next = ep->Next;
  97                                 ep->PollingAtoms = -1;  // Mark as removed
  98                                 ep = prev;      // Make sure prev is kept valid
  99                                 continue ;
 100                         }
 101
 102                         // Read data
 103                         // TODO: Check the endpoint
 104                         // TODO: Async checking?
 105                         // - Send the read request on all of them then wait for the first to complete
 106                         USB_RecvDataA(
 107                                 ep->Interface, ep->EndpointIdx+1,
 108                                 ep->MaxPacketSize, ep->InputData,
 109                                 ep->Interface->Driver->Endpoints[ep->EndpointIdx].DataAvail
 110                                 );
 111
 112                         // Call callback
 113
 114                         // Reschedule
 115                         if( period_in_atoms != POLL_SLOTS )
 116                         {
 117                                  int    newqueue_id = (giUSB_PollPosition + period_in_atoms) % POLL_SLOTS;
 118                                 tUSBEndpoint    **newqueue = &gUSB_PollQueues[newqueue_id];
 119
 120                                 prev->Next = ep->Next;
 121
 122                                 ep->Next = *newqueue;
 123                                 *newqueue = ep;
 124                                 ep = prev;
 125                         }
 126                 }
 127                 giUSB_PollPosition ++;
 128                 if(giUSB_PollPosition == POLL_SLOTS)
 129                         giUSB_PollPosition = 0;
 130                 // TODO: Check for a longer delay
 131                 Time_Delay(POLL_ATOM);
 132         }
 133 }
 134